Ticker Text demo question / maybe issue

[JonRobert]

I'm using the example "TickerTextDemo.ino" with some minor modifications. 1) changed to 128 x 32 2) shortened message 3) added some print lines for debug / understanding.

My goal is to understand enough to run Ticker test in the beginning on my program (perhaps in Setup) then move on to my program code. I haven't figured out what to include in what I hoped could be a function that would Ticker the text then stop.

Issue I've noticed: (or maybe my misunderstanding)

uint8_t rtn = oled.tickerTick(&state); if (rtn <= RTN_CHECK) { // returns FALSE every loop except when 1st char of the message reaches the left edge, in this case its 16 in which case it is TRUE

Can you tell me how to

• know when the message is fully off the left edge of the active area so I can stop the Ticker
• stop ticker and move on to other code?

BTW I think you've created and offered a great library. I've used it often with good success.

Thank you

John

Full modified Code:

`// Simple Ticker demo for I2C 128x32 oled.

// The ticker shifts text through a one line field on the display. // A queue of text pointers is maintained by the ticker. You must // not modify a text string while its pointer is in the queue. // The display queue size is define by TICKER_QUEUE_DIM in SSD1306Ascii.h.

// tickerTick() returns the current length of the display pointer queue. // If tickerText() is called for a return <= one, the display is continuous. // If tickerText() is called for return zero, all text will be shifted off // the display before another string starts. //

include

include "SSD1306Ascii.h"

include "SSD1306AsciiWire.h"

define I2C_ADDRESS 0x3C

SSD1306AsciiWire oled;

// Ticker display

define RTN_CHECK 1 // Try values of zero or one for RTN_CHECK.

define numberLoops 3

define tickerRate 50 // milliseconds

TickerState state; // Ticker state. Maintains text pointer queue and current ticker state. const char* text[] = { "Prog: blah blah v0.02 " }; // this is an array of pointers to the text. uint32_t tickTime = 0; int n = 0; // Ticker display end

//------------------------------------------------------------------------------

void setup() {

Serial.begin(115200); delay(1000); Wire.begin(); Wire.setClock(400000L);

oled.begin(&Adafruit128x32, I2C_ADDRESS);

// Use , field at row 2, mag2x, columns 16 through 100. oled.tickerInit(&state, ZevvPeep8x16, 2, false, 16, 100);

oled.displayRemap (true);

// Try this for full screen width with set1X. // oled.tickerInit(&state, Adafruit5x7, 2); }

void loop() {

if (tickTime <= millis()) { tickTime = millis() + tickerRate;

// Should check for error. rtn < 0 indicates error. uint8_t rtn = oled.tickerTick(&state);

if (rtn <= RTN_CHECK) {     // <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< returns false every loop except when 1st char of the message reaches the left edge, in this case its 16
  // Should check for error. Return of false indicates error.
  oled.tickerText(&state, text[(n++)%3]);
  Serial.println(".........................rtn test true");
}
else{
  Serial.println("rtn test false");
}

}

} // -- end loop -- `

[greiman]

oled.tickerTick() returns how many strings are queued to be displayed. You can add another string when the return value is less than TICKER_QUEUE_DIM by calling oled.tickerText().

When the return value is zero, all strings have been displayed.

[greiman]

  /**
   * @brief Advance ticker by one pixel.
   *
   * @param[in,out] state Ticker state.
   * @return Number of entries in text pointer queue.
   */
  int8_t tickerTick(TickerState* state);

I should add that return of -1 indicates an error.

[JonRobert]

BG wrote: oled.tickerTick() returns how many strings are queued to be displayed. You can add another string when the return value is less than TICKER_QUEUE_DIM by calling oled.tickerText(). When the return value is zero, all strings have been displayed.

the below never printed.

       Serial.println("                     >>>>>> finished displaying all strings");

I never received a oled.tickerTick() of "0" Perhaps I'm doing something wrong or I misunderstood.

My Code:

// Simple Ticker demo for I2C 128x32 oled.
//
// oled.tickerTick() returns how many strings are queued to be displayed. You can add another string when the return value is less than TICKER_QUEUE_DIM by calling oled.tickerText().
//  When the return value is zero, all strings have been displayed.
//

#include <Wire.h>
#include "SSD1306Ascii.h"
#include "SSD1306AsciiWire.h"

#define I2C_ADDRESS 0x3C

SSD1306AsciiWire oled;

// Ticker display
#define RTN_CHECK   1   // Try values of zero or one for RTN_CHECK.
#define numberLoops 3
#define tickerRate 50   // milliseconds
TickerState state;      // Ticker state. Maintains text pointer queue and current ticker state.
const char* text[] = {
    "Prog:  blah blah v0.02    "   //  26 char  26 x (8 + 3) = 286, close to the 289 we counted in the number of "false" loops.
};    // this is an array of pointers to the text.
uint32_t tickTime = 0;
int n = 0;
// Ticker display end

//  Setup
void setup() {
    Serial.begin(115200);
    delay(1000);
    Wire.begin();
    Wire.setClock(400000L);
    oled.begin(&Adafruit128x32, I2C_ADDRESS);
    // Use <font>, field at row 2, mag2x, columns 16 through 100.
    oled.tickerInit(&state, ZevvPeep8x16, 2, false, 16, 100);
    oled.displayRemap (true);
    // Try this for full screen width with set1X.
    // oled.tickerInit(&state, Adafruit5x7, 2);
    oled.clear();
}

//----------------------------- Main

void loop() {
    if (tickTime <= millis()) {
        tickTime = millis() + tickerRate;

   // Should check for error. rtn < 0 indicates error, rtn of 0 indicates all strings have been displayed.
        uint8_t rtn = oled.tickerTick(&state);

        if (rtn == 0){
            Serial.println("                                         finished displaying all strings");
        }

        if (rtn <= RTN_CHECK) {     // rtb = false every loop except when 1st char of the message reaches the left edge
            // Should check for error. Return of false indicates error.
            oled.tickerText(&state, text[(n++)%3]);
            Serial.println(".........................rtn test true");
        }
        else{
            Serial.println("rtn test false  ");
            return;
        }
    }
}  // -- end loop --
//  -- eof --

[greiman]

Yes you will never get return zero since you always queue another copy of the string here when rtn == 1.

 if (rtn <= RTN_CHECK) {     // rtb = false every loop except when 1st char of the message reaches the left edge
            // Should check for error. Return of false indicates error.
            oled.tickerText(&state, text[(n++)%3]);  <<------ Causes another copy of your string to be queued when rtn == 1.
            Serial.println(".........................rtn test true");
        } else{
            Serial.println("rtn test false  ");  <<----- This is not false it is more than one copy queued.
            return;
        }

[JonRobert]

Got it :) Thanks